After continuing to see weird test failures, did some more careful testing,
discovered that CI can pause a machine entirely for up to 29 seconds
or so very rarely, and 5-10 seconds quite frequently, which causes
cascading heartbeat failures and so on. Remove those.
It turns out that it's desireable to be able to configure the bootstrap
timeout for etcd, because during startup, we end up delaying that long
(N-1) times in series during each cluster creation, which is pointless
when we're starting the whole cluster. Reduces test runtime by several
minutes.
CI systems sometimes hiccup for five seconds, which causes heartbeat leases
to fail and breaks all sorts of things. As a workaround, update heartbeat
TTL for tests only. This might in turn cause different failures to do
with leader elections, but in theory those should be handled now?
In nearly all cases, we can just switch ioutil.TempDir->testhook.TempDir
and similarly for TempFile. There's one case where we can't because we
need files to be removed before tests are over.
Also in the process give identifiable names to a lot of temporary files
and make sure they're being cleaned up, and don't use "/tmp/foo" as a
file name in a test that could be running in more than one test process
at once. :)
Long story short: Once we create a server and start it, we can't start
it again. We can't close it and restart it, and we can't just start
it without closing it.
Unfortunately, if the server's config needs to change, we have a Problem
here.
This ultimately means that the retry logic for GetListeners can't actually
retry successfully; if we fail on the first attempt, we necessarily fail
on any later attempts also, and if we try to fix that, we get panics.
But!
We don't actually NEED to retry. We just need to ensure that we can
open a :0 port, extract the actual port number, and use that in places
where the port number mattered, without having to rebind it.
The only actual place we needed to rebind things was opening gRPC
servers, so we introduce a gRPC Listener that can be used instead of
trying to bind to a specified port.
In a bunch of other cases where we had similar logic to try to allocate
and then use a port, we can switch to just using a provided listener.
For instance, net/http has `Serve(net.Listener, handler)`, not just
ListenAndServe(addr, handler).
This should eliminate the weird CI failures from eaddrinuse.
NOT fixed: server/cluster_test.go/TestClusterResize_AddNode isn't working
right now. The new node isn't actually being added to the existing cluster.
I attempted this but was outsmarted by it, and I think fixing the
rest of this is worth it as a separate thing.
port mapper gives out ports from 63000-65000 for the tests
fix another race
http test uses port.MustGetPort
rbf: remove :0 port request
ocd happy
test fix for grpc listener address already in use
test/disco allocates BindGRPC port from the port mapper
dump stack on each GetPort
verify each port is usable right away
server/config.go has Config.Validate() now
panic if gossip port is 0. validate server.Config
fix another gossip port 0
builds
quiet, don't dump stack on each port alloc
builds
happy linter
even gossip fallback should not be zero but rather use the port mapper
